Let's define this short function:
const baseUrl = url => url.indexOf('?') === -1 ? url : url.slice(0, url.indexOf('?'));
// Note that `includes` isn't supported in IE 11 const baseUrl = url => url.includes('?') ? url.slice(0, url.indexOf('?')) : url;
baseUrl('https://domain.com/path/sub/path?foo=bar&hello=world'); // 'https://domain.com/path/sub/path'